Useful clinical rules save on radiographs and need to be used widely What could possibly be more straightforward than the assessment of an injured ankle? Patients with ankle injuries, usually sustained recreationally or in a simple fall, attend emergency departments throughout the world in their hundreds of thousands every year. Most of these patients will have sustained simple injury to ligamentous soft tissue or a small avulsion fracture of no clinical significance. A minority will have sustained more serious fractures, requiring immobilisation or internal fixation. Patients with ankle injury constitute approximately 5% of all patients who visit emergency departments, although fewer than 15% of these patients will have clinically significant fractures. Differentiating between these two groups of patients is not always easy, particularly for relatively inexperienced clinicians. The safety net for indeterminate examination has always been recourse to radiography. However, such an unselective policy has resulted in inestimable numbers of unnecessary exposures …